Ordinary passport holders from Bangladesh are required to apply for a visa to Turkey.

You can apply here:  https://turkishvisa.com/

Keep in mind that you must meet all the requirements listed below in order to obtain an e-Visa:

1. I am traveling for the purposes of tourism or business.

2.  I hold a valid supporting document  (Schengen visa or a valid visa from any of the OECD member countries; or a valid residence permit of a Schengen or OECD country). Please note that e-Visas are not accepted as a supporting document.

3. I can prove that I hold a return ticket, hotel reservation and at least 50 $ per each day of my stay.
4. I hold a passport valid for at least 6 months from the date I intend to enter Turkey.
5. I have a round-trip ticket with Turkish Airlines or Pegasus Airlines.

NOTE - Bangladeshi nationals holding diplomatic and official/service passport are exempted from visa to Turkey for travels up to 90 days.